**DRAW CIRCLE, DRAW DISK (original enhancement)**

DRAW circle

draws a circle of radius 1 and of center the origin with the line color.

The beam shall be set off.

DRAW disk

draws a circle and fill the interior of it with the area color.

The beam shall remain.

These can be transformed. For example,

if you want to draw a circle of radius *r*, center (*x*,*y*), write

`DRAW circle WITH SCALE(`

*r*)*SHIFT(*x*,*y*)

Refer to picture definition

<Note>

CIRCLE and DISK are not reserved words.

Thus a user can define a picture of its name "CIRCLE" or "DISK".

<Note>

If the circle crosses a line at infinity as a result of transformation, The DRAW statements above do not draw proper figures.

On such a case, the following picture definition is effective.

1000 EXTERNAL PICTURE circle 1010 OPTION ANGLE DEGREES 1020 FOR t=0 TO 360 1030 PLOT LINES : COS(t),SIN(t); 1040 NEXT t 1050 END PICTURE 2000 EXTERNAL PICTURE disk 2010 OPTION ANGLE DEGREES 2020 OPTION BASE 0 2030 DIM x(359),y(359) 2040 FOR t=0 TO 359 2050 LET x(t)=COS(t) 2060 LET y(t)=SIN(t) 2070 NEXT t 2080 MAT PLOT AREA : x,y 2090 END PICTURE